In optical systems involving the generation and controlled radiation of long or continuous pulses of light, such as spectroscopy, or solar simulation, where high intensity, color correct illumination of sensitive working areas is required, such as in projection systems fiber optics illumination devices, it is advantageous to have a light source capable of producing the highest possible light flux density. Products utilized in such applications include short arc inert gas lamps, which may also be referred to as arc lamps. At least one conventional arc lamp includes a sealed chamber, which contains a gas pressurized to several atmospheres, and an opposed anode and cathode defining an arc gap. The conventional arc lamp further includes a window to provide for the transmission of the generated light and a reflector body surrounding the arc gap. The reflector body may be a ceramic reflector body.
During operation of the conventional arc lamp, the anode and the cathode generate a significant amount of heat. The anode and the cathode are inside the sealed chamber of the arc lamp. As a result, the reflector body is also subjected to high heat during operation of the arc lamp. Typically, heat is transferred from the sides of the arc lamp. The operating power of the arc lamp may be limited by how fast the reflector body cools off. The faster the reflector body cools off, the higher the operating power of the arc lamp may be. Furthermore, the reflector body is susceptible to cracking when operated at high temperatures over a long period of time. Cracking of the reflector body may cause the arc lamp to explode, leading to property damages and/or personal injuries.
One existing technique to cool off an arc lamp is to couple a single cooling fan to the back of the arc lamp. The cooling fan may be mounted to the back of a housing holding the arc lamp. However, the above technique is unsatisfactory because of several reasons. One reason is that the single cooling fan is usually too tall and bulky for tabletop mounting applications (e.g., in a tabletop video projection system) because a smaller fan would not be able to cool off the arc lamp to a safe temperature at an acceptable speed. Furthermore, the cooling fan is generally very noisy (e.g., having a noise level above approximately 36 dB) because of the size of the cooling fan. Thus, fan noise has frequently been an issue with arc lamp assemblies. The fan noise issue is particularly problematic for projection systems because such noise may distract the audience viewing a display by the projection system.